US12068700B2ActiveUtilityA1
Piezoelectric motor energy-saving control method based on an iterative learning
Est. expiryFeb 13, 2040(~13.6 yrs left)· nominal 20-yr term from priority
H02N 2/001H02N 2/0075
42
PatentIndex Score
0
Cited by
12
References
11
Claims
Abstract
An iterative learning-based energy-saving control method for a piezoelectric motor, comprising: setting a sampling period of a piezoelectric motor ( 101 ); obtaining an expected output trajectory of the piezoelectric motor, and performing sampling according to the sampling period to obtain a sampled expected output sequence ( 102 ); setting an initial control input signal of the piezoelectric motor ( 103 ); obtaining an actual control input signal according to a mapping relation of the initial control input signal, and transmitting the actual control input signal to the piezoelectric motor to obtain an actual output position ( 104 ); obtaining a mapping relation of the output position of the piezoelectric motor according to the actual output position, and sampling the mapping relation according to the sampling period to obtain a sampled actual output sequence ( 105 ); calculating the difference between the sampled expected output sequence and the sampled actual output sequence to obtain a sampling error function sequence ( 106 ); obtaining an iterative learning gain parameter by calculation according to a preset convergence condition ( 107 ); and obtaining, by calculation according to the sampling error function sequence and the iterative learning gain parameter, an iterative input voltage required by iteration of the piezoelectric motor, and transmitting the iterative input voltage to the piezoelectric motor ( 108 ).
Claims
exact text as granted — not AI-modifiedThe invention claimed is:
1. A piezoelectric motor energy-saving control method based on an iterative learning, comprising:
setting a sampling period of a piezoelectric motor;
obtaining an expected output trajectory of the piezoelectric motor, and performing a sampling according to the sampling period to obtain a sampled expected output sequence;
setting an initial control input signal of the piezoelectric motor;
obtaining an actual control input signal according to a mapping relationship of the initial control input signal, and transmitting the actual control input signal to the piezoelectric motor to obtain an actual output position of the piezoelectric motor;
obtaining a mapping relationship of an output position of the piezoelectric motor according to the actual output position, and performing a sampling on the mapping relationship of the output position of the piezoelectric motor according to the sampling period to obtain a sampled actual output sequence;
performing a difference calculation between the sampled expected output sequence and the sampled actual output sequence to obtain a sampling error function sequence;
calculating an iterative learning gain parameter according to a preset convergence condition;
calculating an iterative input voltage required by the piezoelectric motor for performing iterations according to the sampling error function sequence and the iterative learning gain parameter, and transmitting the iterative input voltage to the piezoelectric motor.
2. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 1 , wherein after transmitting the iterative input voltage to the piezoelectric motor, the method further comprises: repeating steps of the iterations until the sampling error function sequence is smaller than a preset allowable error value range, stopping the iterations.
3. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 1 , wherein the step of setting the sampling period of the piezoelectric motor is: setting the sampling period T s of the piezoelectric motor, the sampled discrete sequence is
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
T
S
⌋
}
;
then a corresponding discrete time series is:
t
∈
{
0
,
T
S
,
2
T
S
,
…
,
⌊
T
T
S
⌋
·
T
S
}
;
where t is a running time.
4. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 3 , wherein the step of obtaining an expected output trajectory of the piezoelectric motor, and performing a sampling according to the sampling period to obtain a sampled expected output sequence comprises: obtaining the expected output trajectory y d (t), performing the sampling according to the sampling period T s to obtain the sampled expected output sequence y d (n·T s ),
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
T
S
⌋
}
,
and defining the sampled expected output sequence as ŷ d (n).
5. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 4 , wherein the step of setting the initial control input signal of the piezoelectric motor comprises: setting an initial continuous input signal of the piezoelectric motor as ũ 0 (t), which satisfies:
u
~
0
(
t
)
=
{
u
~
0
(
0
)
,
t
∈
[
0
,
T
S
)
u
~
0
(
T
S
)
,
t
∈
[
T
S
,
2
T
S
)
⋮
u
~
0
(
⌊
T
T
S
⌋
·
T
S
)
,
t
∈
[
⌊
T
T
S
⌋
·
T
S
,
T
]
.
6. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 5 , wherein the mapping relationship of the initial control input signal is:
u
k
(
t
)
=
{
u
~
k
(
t
)
,
t
∈
[
0
,
T
k
]
0
,
t
∈
(
T
k
,
T
]
;
wherein u k (t) is the actual control input signal.
7. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 6 , wherein the mapping relationship of the output position of the piezoelectric motor is:
y
~
k
(
t
)
=
{
y
k
(
t
)
,
t
∈
[
0
,
T
k
]
y
k
(
t
)
+
∫
T
k
t
Ce
A
(
t
-
τ
)
B
u
~
k
(
τ
)
d
τ
,
t
∈
(
T
k
,
T
]
,
wherein y k (t) is the actual output position, and {tilde over (y)} k (t) is the mapping relationship of the output position of the piezoelectric motor;
the step of performing the sampling to obtain the sampled actual output sequence is: performing the sampling on {tilde over (y)} k (t) according to the sampling period T s to obtain the sampled actual output sequence {tilde over (y)} k (n·T s )
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
T
S
⌋
}
,
and defining the sampled actual output sequence as ŷ k (n), specifically as follows:
y
^
k
(
n
)
=
{
y
k
(
n
·
T
S
)
,
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
k
T
S
⌋
}
y
k
(
n
·
T
S
)
+
∫
T
k
n
·
T
S
Ce
A
(
n
·
T
S
-
τ
)
B
u
~
k
(
τ
)
,
n
∈
{
⌈
T
k
T
S
⌉
,
⌈
T
k
T
S
⌉
+
1
,
…
,
⌊
T
T
S
⌋
}
.
8. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 7 , wherein a specific algorithm for performing the difference calculation between the sampled expected output sequence and the sampled actual output sequence is: ē k (n)=ŷ d (n)−ŷ k (n); then the sampling error function sequence is:
e
^
k
(
n
)
=
{
e
_
k
(
n
)
,
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
k
T
S
⌋
}
e
_
k
(
n
)
-
∫
T
k
n
·
T
S
Ce
A
(
n
·
T
S
-
τ
)
B
u
~
k
(
τ
)
d
τ
,
n
∈
{
⌈
T
k
T
S
⌉
,
⌈
T
k
T
S
⌉
+
1
,
…
,
⌊
T
T
S
⌋
}
,
then defining:
ê k ( T )= y d ( T )− {tilde over (y)} k ( T )−∫ T k T Ce A(T−τ) Bũ k (τ) dτ.
9. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 8 , wherein the preset convergence condition is: ∥I−LCB∥≤ρ<1.
10. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 9 , wherein the steps of calculating an iterative input voltage required by the piezoelectric motor for performing iterations according to the sampling error function sequence and the iterative learning gain parameter, and transmitting the iterative input voltage to the piezoelectric motor comprise:
according to the sampling error function sequence and the iterative learning gain parameter, an iterative learning control law is set as:
u
~
k
+
1
(
n
·
T
S
)
=
u
~
k
(
n
·
T
S
)
+
L
e
^
.
k
(
n
)
,
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
T
S
⌋
}
,
wherein ũ k+1 (t) represents a control input signal of the piezoelectric motor in a k+1 -th iteration, {circumflex over (ė)} k (n) represents control input signal of the piezoelectric motor in a k -th iteration, and an derivative {circumflex over (ė)} k (n) of the sampling error function sequence is calculated as follows:
e
^
.
k
(
n
)
=
{
e
^
k
(
(
n
+
1
)
)
-
e
^
k
(
n
)
T
S
,
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
T
S
⌋
-
1
}
e
^
k
(
T
)
-
e
^
k
(
n
)
T
S
,
n
=
⌊
T
T
S
⌋
,
wherein according to the iterative learning control law, updating the control input signal ũ k+1 (t) of a next iteration, and ũ k+1 (t) satisfies:
u
~
k
+
1
(
t
)
=
{
u
~
k
+
1
(
0
)
,
t
∈
[
0
,
T
S
)
u
~
k
+
1
(
T
S
)
,
t
∈
[
T
S
,
2
T
S
)
⋮
u
~
k
+
1
(
⌊
T
T
S
⌋
·
T
S
)
,
t
∈
[
⌊
T
T
S
⌋
·
T
S
,
T
]
.
11. The piezoelectric motor energy-saving control method based on an iterative learning according to claim 2 , wherein the step of setting the sampling period of the piezoelectric motor is: setting the sampling period T s of the piezoelectric motor, the sampled discrete sequence is
n
∈
{
0
,
1
,
2
,
…
,
⌊
T
T
S
⌋
}
;
then a corresponding discrete time series is:
t
∈
{
0
,
T
S
,
2
T
S
,
…
,
⌊
T
T
S
⌋
·
T
S
}
;
where t is a running time.Cited by (0)
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